Interpretive Summary: We evaluated bactericidal activities of several antimicrobial wine recipes consisting of red and white wine extracts of oregano leaves with added garlic juice and oregano oil against the following foodborne pathogens: Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica. Studies designed to optimize antibacterial activities of the recipes showed that several combinations of the naturally occurring plant-derived ingredients rapidly inactivated the four pathogens. Polyphenolic compounds isolated by chromatography from red wine exhibited high antimicrobial activity at nanogram levels against two strains of Bacillus cereus. These activities are similar to those we previously reported for tea flavonoids. Wines appear to be useful solvents for plant-derived antimicrobial formulations to reduce pathogens in foods. These include potential uses as antimicrobial beverages, food marinades, oral hygiene rinses, and as disinfectants of contaminated nonfood items such as meat cutting boards. Because the formulations were tested under laboratory conditions, additional studies are needed on their effectiveness, compatibility, sensory properties, and safety in various applications.

Technical Abstract:
We evaluated bactericidal activities of several antimicrobial wine recipes consisting of red and white wine extracts of oregano leaves with added garlic juice and oregano oil against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica. Dose-response plots were used to determine the percentage of the sample that induced a 50% decrease in colony-forming units (CFU) at 60 min (BA50). Studies designed to optimize antibacterial activities of the recipes showed that several combinations of the naturally occurring plant-derived ingredients rapidly inactivated the four foodborne pathogens. Additional studies showed that (a) incubation temperature affected activities in the following order: 37 oC > 21 oC > 4 oC; (b) varying the initial bacterial load from 103 to 105 CFU/well did not significantly affect BA50 values; (c) storage of three recipes up to two months did not change their effectiveness against Salmonella enterica; and (d) polyphenolic compounds isolated by chromatography from red wine exhibited exceptional activity at nanogram levels against two strains of Bacillus cereus. These observations suggest that antimicrobial wine formulations have the potential to improve the microbiological safety of foods.